Rob's Blog

Pa Annoyed has what I think is a very important explanation of the problems with doing statistics on the kinds of signals found in climate science. It’s important because it makes available to the layman a level of understanding about the nature of the science. And understanding helps us come up with good arguments.

The article starts off about an email from dendrochronologist Ed Cook’s in which he complains that he has to review a paper that contains too much maths. Pa Annoyed points out that it’s exactly the kind of maths he should be intimately familiar with.

Pa Annoyed then proceeds to explain the kind of maths we are talking about. It is about how to tell the difference between signal and noise. The problem is there are different kinds of forms that the signal and the noise can take, and climatologists seem very keen to assume that the signal is a straight line and the wobbles up and down are noise. The straight line goes steadily up and is global warming; the noise wobbles up and down and is weather.

Pa Annoyed explains that there is no physical reason for that to be the signal to be a straight line, and every reason for it to be what the graphs actually look like: a random walk. In other words, there can be other hypotheses that fit the data.

Read the whole thing. Really. Read it now. You’ll learn something.

I don’t see how one mistake in a 3,000-page report can damage the credibility of the overall report

So says Dr van Ypersele. I can see how. If you say all the Himalayan Glaciers will disappear by 2035 in the IPCC’s 4th annual report and the IPCC has no idea where the figure came from, it makes people wonder just how much other made up stuff is in there. The date is wildly inaccurate:

“You just can’t accomplish it,” Jeffrey Kargel from the University of Arizona told BBC News at the time.

“If you think about the thicknesses of the ice – 200-300m thicknesses, in some cases up to 400m thick – and if you’re losing ice at the rate of a metre a year, or let’s say double it to two metres a year, you’re not going to get rid of 200m of ice in a quarter of a century.”

The row continues in India, with Environment Minister Jairam Ramesh calling this week for the IPCC to explain “how it reached the 2035 figure, which created such a scare”.

Lots of blog posts seem to start this way, lately. The really great thing about the cold weather, though, is that it forces those who say the planet is warming to explain themselves. This inevitably illustrates that measuring the climate is complicated, which means that just maybe it is possible that it can be done wrong. The CO2-causes-warming-and-look-how-warm-it-is narrative is no more.

Just imagine how different things would be if the weather was warm. It would be obvious that global warming is happening, so there would be no need for the man in the street to question it.

You can judge a man by the company he keeps. Mugabe spoke at Copenhagen.

Climate change, the latest and by far the most encompassing and insistent crisis spawned by this hegemonic development paradigm, yet again reveals the interconnectedness issues of global imbalances by way of uneven development, by way of unfair trade, by way of unclean politics, by way of hegemonic values and by way of arbitrary power and governance systems.

Yep, nobody could accuse Mugabe of wielding arbitrary power. Let’s listen to his ideas about governance systems.

Why is the guilty north not showing the same fundamentalist spirit it exhibits in our developing countries on human rights matters on this more menacing question of climate change? Where is its commitment to retributive justice which we see it applying on other issues? Where is sanctions for climate change offenders?

Never mind Mugabe is up to in Zimbabwe, the weather is getting warmer.

By the way, all the rubbish about lungs of the planet and “we who tend the forest so badly needed to heal the ecosystem” that Mugabe witters on about is dealt with by Pa Annoyed. The rainforest is only the lungs of the rainforest.

You’d think Ian Hislop would be all over climategate. Government pays scientists and they say things that are very convenient to government. But on Have I Got News For You this evening he sneered at the blogosphere for being bonkers and mentioning Hitler all the time, and went on about how there are actually real scientists who know all about climate change and it’s only Sarah Palin and the Daily Mail who say otherwise.

James May didn’t agree, and got accused of getting his opinions from Jeremy Clarkson and hissed at by the audience for saying he didn’t care about the planet. Reginald D Hunter seemed somewhat skeptical too, but he was being funny (he *is* funny) so it’s hard to say what he really thinks.

Still, it’s another sign in the mainstream media that there is a debate going on.

Update: Via Brian Micklethwait: James Delingpole on Private Eye’s uselessness on this issue.

Have I Got News for You: Season 38 Episode 8

Skeptical Science examines the science of climate skepticism. From what I’ve seen of it they avoid the tendency of warmists to argue from authority.

The point of the Hockey Team’s research is to show that recent warming is unprecedented. Skeptics argue that tree ring proxies are unreliable and that the medieval warm period was warmer, or about as warm as, current temperatures. Skeptical Science argues that you can get a hockey stick without tree rings. It’s a good, honest looking article.

The first three graphs show temperatures determined from boreholes, stalagmites and glaciers respectively. But these series only go back as far as 1500, not to the medieval warm period. But:

When you combine all the various proxies, including ice cores, coral, lake sediments, glaciers, boreholes & stalagmites, it’s possible to reconstruct Northern Hemisphere temperatures without tree-ring proxies going back 1,300 years

The source? Mann 2008 (and a broken link at the time of writing, unfortunately).

The graph that accompanies this is interesting. It’s a little too small, but the steep red line is the CRU land based temperature record, which is subject to climategate. The steep grey line is another land based temperature record called HAD. I think this refers to the Hadley Centre which is the Met Office’s climate research centre. I’m not sure what the connection is but there are data sets referred to as HADCRU. In any case all land temperature measurements are suspicious because of urbanisation.

None of the other lines look particularly impressive regarding current warmth compared to medieval warmth. The dark blue line is “CPS land+ocn with uncertainties”, whatever that is. The pink line (Moberg et al) doesn’t look alarming at all.

There is another worry about all these proxies, described by Bod in response to Michael Jennings’ post about peer review:

My understanding is that the CRU’s (and GISS’ for that matter) numbers – I hesitate to call it data – are used for calibration purposes, thereby tainting any other research that uses it. This double-damns CRU’s whole research department, right the way back to HADCRU1 and beyond, and should render these people persona non grata across the entire scientific community if what’s been uncovered is true. This is the equivalent of cutting 25.4 mm off the end of the standard metre. (Yeah, I know they don’t use the metre now)

In The Cathedral and the Bazaar, Eric Raymond wrote about why open source software is superior to proprietary software. More people look at the code. Even if you don’t look at the code yourself, it can be nice to know you could. For example, I wouldn’t recommend anyone use proprietary encryption software to send secret messages they don’t want their government to read. How can you be sure there isn’t a bug or even a secret government key that will unlock your message? For the purpose of catching the real bad guys, of course.

With open source software, even if you don’t look at the source code yourself, you can tell that others are looking. You can see the bug reports and see the fixes made. If there was a back door in open source encryption software, someone would be shouting about it.

Oddly enough, the openness of open source software imitates the openness of scientists. They publish their research and other people can see exactly what has been done and check that they can reproduce it. If there is something wrong with it, people start shouting, and the next lot of research refines the knowlege until there are few bugs left.

In climate science there is a lot of software. Software is used to run statistical algorithms on data from thermometers and tree rings and other temperature proxies in an attempt to make some sort of coherent temperature history. This is important for the theory of anthropogenic climate change because it gives us a clue as to whether modern temperatures are extraordinary or not. But frequently research is published in a way that makes it difficult or impossible to reproduce what the researcher did. The details of the research are recorded in the software, but the software is not always released; it is proprietary.

There is no way of knowing what bugs it contains, or even whether there is a back door for the government to get its way. I wouldn’t recommend relying on the output of proprietary software to decide whether those proposing to restructure the world’s economy have got their facts straight.

Eric Raymond has made the same point.

We know, from experience with software, that secrecy is the enemy of quality — that software bugs, like cockroaches, shun light and flourish in darkness. So, too. with mistakes in the interpretation of scientific data; neither deliberate fraud nor inadvertent error can long survive the skeptical scrutiny of millions. The same remedy we have found in the open-source community applies – unsurprisingly, since we learned it from science in the first place. Abolish the secrecy, let in the sunlight.

Not only is it bad software, it is bad science. If other scientists can’t reproduce what you’ve done, then you might as well have not done it.

The release of the CRU files and ensuing analysis is certainly thrilling. Brian Micklethwait writes about why this is a massive story.

Basically, the Global Warming debate has been a gigantic exercise in argument from authority. [...] If the entire argument for Green World Government balances on top of the public claims of a tiny few scientists, whose actual arguments are understood by hardly anybody, but if first emails and now other revelations show those scientists in a quite new and very bad light, not as selfless servants of truth and virtue, but as liars, cheats, frauds, manipulators and bullies, then that will most certainly change things, big time.

In two very huge ways. The pro Green World Government team will lose a lot of support from the baffled onlooker demographic and the anti Green World Government team (mine) will gain a lot of support from that same demographic.

Most of the defense seems to miss this point. Here is a quote of the day from a blog called The Way Things Break:

If you think that global warming rests on a few temperature data sets and models, you are very wrong. If you don’t understand this then you don’t know enough to have an opinion on the subject, and you most likely will be treated just like any other ineducable troll.

This is just an argument from authority. It’s interesting to look at the whole of the comment from which this was taken.

It seems anyone who thinks the “trick” email is damning doesn’t have much experience in the sciences (or computer programming, for that matter). It is a shortcut, a hack, a clever little item to make things a bit easier. It is not an attempt to deceive.

Again this misses the point. We are not fixating on the word “trick”, we are fixating on the word “hide”. From the email:

I’ve just completed Mike’s Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd from 1961 for Keith’s to hide the decline.

Now hide the decline just means to remove the problem of tree rings not being a very good proxy for temperature since about 1960. This is known as divergence, and it’s exactly the sort of thing people want to see discussed as openly as possible. Steve McIntyre has been trying to investigate tree ring proxies for a long time and people in CRU have been less than helpful to him. It would be wrong to focus on just this one email. Some good discussion along these lines is on Power Line. And from the warmists’ side, a reasonable sounding defense of using tree ring data in spite of the divergence can be found in the a comment on Island of Doubt. The argument goes that tree rings fit the thermometer data before 1960 and fit with other proxies before that.

But this starts to depend on statistical methods implemented in source code, and CRU’s software does not seem up to very good standards. If we could all reproduce their results and see exactly what they had done step for step, perhaps we wouldn’t be having this debate.

Back to that first Island of Doubt comment:

Here’s a thought. Assume the worst case scenario that all these emails are actually damning in the extreme. Assume that every bit of science in the emails is to be thrown out.

Do all that, and you still haven’t even come close to invalidating the science of global warming. That is how much other evidence there is out there.

I’m not so sure because all the tree ring data seems pretty key to showing that recent warming is unprecedented. If it’s not unprecedented, then natural variability is the most obvious hypothesis.

Grab a climate textbook and do some reading…it will help if you have some physics background too.

Well, it’s interesting that he should finish on the point because from what I know about the physics, CO2 makes very little difference to temperatures on its own. Feedbacks are needed and these feedbacks are not well understood. With the lack of warming in the last ten years we are left with the alleged “unprecedented” warming and therefore the tree ring proxies being key to the whole AGW case.